As a conventional technique 1, for example, FIG. 6 in Patent Document 1 discloses an integrated thin-film solar battery having a string where a plurality of thin-film photoelectric conversion elements are electrically connected in series.
In the conventional technique 1, the thin-film photoelectric conversion elements are configured so that a transparent electrode layer, a photoelectric conversion layer and a metal electrode layer are sequentially laminated on a transparent insulating substrate, and a power collecting electrode made of a metal bar is jointed onto three or more places of the metal electrode layer of the thin-film photoelectric conversion elements via a brazing filler metal.
Further, as an integrated thin-film solar battery in a conventional technique 2, FIG. 1 of Patent Document 1 discloses an integrated thin-film solar battery having the following constitution.
In this constitution, in thin-film photoelectric conversion elements that joint power collecting electrodes, metal electrode layer and photoelectric conversion layer are partially removed so that grooves are formed, and the power collecting electrodes are buried into the grooves so as to be electrically connected to the transparent electrode layer directly.
This constitution is also disclosed in FIG. 1 of Patent Document 2.
In the integrated thin-film solar batteries in the conventional techniques 1 and 2 where the power collecting electrodes are jointed to the three or more thin-film photoelectric conversion elements, the plurality of thin-film photoelectric conversion elements between the power collecting electrode on one end side and the intermediate power collecting electrode are connected in series so as to form one series-connected string. Further, the series-connected strings adjacent in a series-connecting direction are constituted so that their current directions are opposite to each other.
Further, as a conventional technique 3, FIG. 1 in Patent Document 3 discloses an integrated thin-film solar battery having a constitution such that a power collecting electrode is jointed to only a metal electrode layer of thin-film photoelectric conversion elements on both ends in the serial-connecting direction.
Further, as a conventional technique 4, FIG. 3 in Patent Document 3 discloses an integrated thin-film solar battery having a constitution such that a power collecting electrode is jointed to a metal electrode layer of thin-film photoelectric conversion elements on both ends in a serial-connecting direction and a metal electrode layer of one or more thin-film photoelectric conversion elements between the thin-film photoelectric conversion elements on the both ends.